#include <stdio.h>

int main()
{
    int a = 1;
    int b = 1;
    int c = 1;
    int n = 0;
    printf("请输入要得到第几位斐波那契数");
    scanf("%d", &n);
    while(n > 2)
    {
        c = a + b;
        a = b;
        b = c;
        n--;
    }
    printf("%d", c);
    return 0;
}